Known for his mid-range jumpshot,[1][2][3] Cassell often made clutch baskets late in the fourth quarter to help his team win games.

In his senior year in 1992–93, he averaged 18.3 points, 4.9 assists, and 4.3 rebounds per game and led the Atlantic Coast Conference (ACC) in steals.

Cassell's 1992–93 Seminoles team finished with a 25–10 record and advanced to the Elite Eight in the NCAA Tournament, where they lost to the University of Kentucky's Wildcats.

Playing mostly as a backup to Kenny Smith, Cassell developed a reputation as "clutch" and was usually on the court for the fourth quarter of close games.

Rockets management feared their window of winning another championship with Olajuwon, Drexler and Smith was closing, and looked to trade for another star-caliber player.

After the 1995–96 season, he was traded to the Phoenix Suns, along with Robert Horry, Chucky Brown, and Mark Bryant, in exchange for former league MVP Charles Barkley.

[14] On December 27, 1996, just 22 games into the season, he was traded along with Michael Finley, A.C. Green, and a second-round draft pick to the Dallas Mavericks in exchange for Jason Kidd, Tony Dumas, and Loren Meyer.

Though Cassell had begun to develop chemistry with the Suns and Coach Ainge, team management felt they could not pass up the opportunity to trade for Kidd.

[14] Midway through the 1996–97 season, after appearing in 16 games for the Mavericks, he was traded with Chris Gatling, Jim Jackson, George McCloud, and Eric Montross to the New Jersey Nets in exchange for Shawn Bradley, Ed O'Bannon, Robert Pack, and Khalid Reeves on February 17, 1997.

Led by coach John Calipari, who pushed the team to trade for then re-sign Cassell,[17] the Nets were favorites in the Eastern conference entering the lockout-shortened 1998–99 season.

[24][25] After spending four seasons with the Bucks, he was traded along with Ervin Johnson to the Minnesota Timberwolves in exchange for Joe Smith and Anthony Peeler following the 2003 NBA draft.

Cassell, Latrell Sprewell and Kevin Garnett formed what was widely considered the best trio in the NBA that season,[27] vaulting past Western Conference powerhouses the Sacramento Kings, Dallas Mavericks, San Antonio Spurs and Los Angeles Lakers for the number one seed in the Western Conference, with a franchise-best 58–24 record.

Cassell, who appeared in only 59 games that season due to injuries, voiced his frustration over the midseason firing of Flip Saunders and not being offered a contract extension.

After the 2004–05 season, the Timberwolves traded Cassell and a conditional first-round pick to the Los Angeles Clippers in exchange for Marko Jarić and Lionel Chalmers.

Cassell appeared to have found a home with the Clippers, as he helped lead them back to the playoffs for the first time since 1997, with their best record in team history at 47–35.

[50] On March 4, 2008, Cassell officially signed with the Celtics,[53] but immediately flew back to his hometown of Baltimore to attend funeral services for his deceased family member.

On March 17, 2008, Cassell had a standout performance in a Saint Patrick's Day matchup against the San Antonio Spurs, when he led the team from a 22-point deficit to a 2-point victory, scoring 17 points and hitting a clutch shot late in the game.

During the 2008–09 season, Cassell served as an unofficial assistant to head coach Doc Rivers; though he did not play in any games, he was still officially listed as an active player.

[64] Cassell cleared waivers and was eligible to re-sign with Boston or another contender, but opted to sit out the remainder of the season, and he announced his retirement in May 2009.

[65][67] John Wall, who was drafted first overall by the Wizards in 2010, credits Cassell for his development into one of the NBA's premier point guards and leadership during the team's Eastern Conference semi-finals appearance in 2014 – their first playoff series win since 2005.

[69] After five seasons with the Wizards, Cassell was hired by the Los Angeles Clippers on September 29, 2014, to join Doc Rivers' staff as assistant coach.

In this clip,[74] Cassell explains how to post up against opposing guards, shoot pull-up jump shots and hit buzzer beaters.

He admires retired NBA players Terrell Brandon and Jeff Hornacek, two prolific mid-range shooters after whom he modeled his game.